OK....I may be "overstating"
.... to be more exact, there is a very significant "ATTENUATION" to the sound you will hear through the hood, and there are going to be some frequencies that are much more attenuated than others--which also means that your ability to recognize and use a Doppler Shift with a boat overhead, is at a major disadvantage to YOU without the hood.
I see divers with hoods on all the time, that just can not be reached by yelling sounds or boat sounds underwater--these same divers do react when they are not wearing their hoods....
On the other hand, there are some divers that don't really use their hearing effectively underwater--almost stop using it.....and that is another story
Well speaking for just me, I know I do have some industrial deafness and struggle with some frequencies, however in saying that I have reasonable hearing above water for my age. Below water I can really struggle, my wife can set off her noise maker and I may not hear it, if I have a hood on I most probably not hear it at first. I do hear boats but the trouble is you don't know what you don't hear as you aren't aware of it.
I think that there are generally three groups of divers, those with good hearing, those with some form of hearing loss or limitation, and those who are just not aware of their hearing underwater. The last two groups being more at risk from boat injury.
---------- Post added July 21st, 2013 at 12:08 PM ----------
The complacency of assuming that a SMB on the surface will be seen and avoided by a boat traveling at 25 mph, is an invitation to Darwinian Selection
I don't think anyone here (well I hope not anyway) are saying that the deployment of an SMB WILL save you from boat injury. I agree with you totally that the comment would be in the stupid basket. What it will do is reduce the risk by making you more obvious. Now if the captains distracted, drunk, not looking that way, you will still be hit regardless, if however the SMB highlight's your position to just one person in the boat it might just save your life.
To say one should not deploy an SMB because idiot drivers aim for them, I do understand there are morons out there, however once again we should be looking at the root cause of the issue, its not the SMB on the surface but the idiot using you for target practice. Deal with the root cause. An example would be to blame the school crossing lollypop lady for being hit by an idiot because she had a reflector jacket on. Now I know this is very generalistic (is this a new word for all those anal literalists?
), and if I thought there were a bunch of stupid drives above me I would have to consider how to deal with that, but in general terms, having an SMB up should improve ones chances of not being hit, and being noticed. However as DAN said above "It IS NOT A GUARENTEE that you will still not be hit", thus it cannot be the ONLY thing you do to surface safely. I would however suggest it is ONE of the things you should consider on every dive. Every dive is different.
---------- Post added July 21st, 2013 at 12:15 PM ----------
I frequently shore dive in places that boats aren't allowed or with a dive flag that I use to ascend/descend. I always have my SMB and spool if needed and can deploy at any time.
We don't dive boats that often but when we do they are usually anchored and we try to return to the anchor line. If for some reason we don't return to the anchor line or its a drift dive, yes, I deploy the SMB.
Not every dive, though, because so many of our dives simply don't require it, although I may start experimenting with using it as a visual aid for ascending, especially since I've had a few bouts of vertigo in cold water/low vis in the past year.
---------- Post added July 20th, 2013 at 11:55 AM ----------
Try Lake Pleasant(not), in AZ.
We've had boaters trying to launch they're boats directly into the water with multiple classes,four dive flags and 3 sun tents full of dive gear right next to the shore. Not one or two boaters, either. One day, my husband chased off more than 20 boats who wanted to launch because they didn't want to wait in line at the boat ramp. Not to mention 5-6 other boats trying to circle around in the area while waiting to load their boats back onto their trailers. If my husband hadn't chased them off, the boats would have been launching literally on top of the OW classes. I have no idea what these boaters think the dive flags are for but they clearly don't realize there are divers in the water. My husband took down plates and reported all of them but I seriously doubt anything was ever done.
Now, this was an exceptionally busy holiday weekend and the usual area for divers was closed off, but we were still diving in an approved area, along with classes from several shops.
Every time we go to the lake we end up chasing off at least a few boaters. I hate it. One day, we had a nice cove to ourselves for a Rescue Class, until a family with two jet skis and a fishing boat decided to start tearing up the cove, using the dive flag as an obstacle for the jet skis! I'm amazed that there aren't more swimmer and diver vs boat injuries on that lake every summer. Plus, I often see divers/classes without flags. Not to mention all the families with little kids playing and swimming in the water, too!
---------- Post added July 20th, 2013 at 11:57 AM ----------
Well that makes so much sense!
Do you not have the water police there? I am amazed of the boating issue, I guess in OZ we don't have the population growth, thus the huge boating population as you have in the US. I think most times in Melbourne, if you are away from the boat launch areas, you would have to fire off a distress flare, to get a boat close enough to hit you unless it was your dive boat or you are in a shipping channel (TONGUE IN CHEEK).
Clearly we are not exposed to the higher level of risk that you are in US and perhaps UK. Deploying an SMB here usually gets the respect it deserves. From all your comment, clearly in the US it does not and something for us foreigners to remember when diving there.
---------- Post added July 21st, 2013 at 12:19 PM ----------
I carry one SMB with a finger reel on every dive and use it on most. Here in Bali, currents can make it impossible to ascend in the spot where the boat dropped you. I shoot the SMB up on every dive from the depth where one of the divers thumbed the dive. This helps ascent for divers who may struggle with buoyancy, such as students.
When diving sidemount, solo or deco, I always carry 2 SMBs. I've trained my captains and crew in a technique I learnt back home:
When in an emergency shoot your first SMB (red one with your name in big letters). Then write what the problem is on your slate and what assistance may be required. Shoot the slate up by tying it on your second SMB (yellow one with emergency written in big letters). This SMB is shot along the same line. When the boat sees these 2 SMBs moving up and down together), the captain approaches, while the crew ready themselves to send the drop tank with extra weight along the line. When this has been achieved, they will detach the slate from the SMB and comply with further instructions (call ER, send support diver, get the bananas and mars bars down here, etc).
SMBs can be used in multiple ways and are the easiest way to establish communication between divers and surface support or to signal passing boats that divers are right under it. All AOW & up should be trained in its basic use (shooting it up). It's regrettable that very few courses make its deployment a requirement. It's repeated use during training should be compulsory for most divers.
Only the few divers who dive in a limited number of environment (the non-traveling diver) and in special conditions (lakes, quarries, caves, etc) will not find it useful during one dive or another. The rest of us should learn how to use it. When you do your next course, do ask your instructor to teach you this essential skill. It can save your life!
This has been my experience in Bali and one I agree with totally. This is how I was taught to dive and carry 2 SMB (yellow and orange) with 2 spools and slate. It appeared normal and expected in Bali to shoot your SMB while at safety stop.
Clearly what it does is to highlight that each country and dive area is different in this respect and one we must all keep in mind. I will have to rethink my actions in the US I expect over other countries and dive locations.
